1. Field of the Invention:
This invention relates to a recording and/or reproducing apparatus and more particularly to a recording and/or reproducing apparatus selectively using one kind of head among different kinds of heads, depending on the kind of recording medium to be used.
2. Description of the Prior Art:
In this specification, magnetic recording and/or reproducing apparatus of the rotary two-head type using a magnetic tape as the recording medium (hereinafter called VTR) will be described by way of example.
During recent years, there have been conspicuous improvements in the properties of magnetic materials. For example, magnetic recording density on a recording medium has been improved by the use of an alloy powder tape (hereinafter called the metal tape), a vapor deposition or evaporation tape, or the like. As a result, it has recently become possible to record signals of 4 to 5 MHz even at a relative speed of 3 m/sec. At present, approximately the same picture quality can be obtained from the metal tape and the evaporation tape. It is difficult to predict what kind of tape will be chiefly used in the future. Therefore, it is desirable for the current VTR's to permit video signal recording on both the metal tape and the evaporation tape by advantageously utilizing their respective characteristics and also to reproduce recorded video signals from both.
However, the metal tape has a large coercive force as a magnetic characteristic. When the metal tape is used, therefore, magnetic recording cannot be adequately accomplished with a head employing ferrite or the like as a core member. Hence, VTR's adapted for use with the metal tape generally use a head employing Sendust, which is an Fe-Si-Al alloy. However, the head employing Sendust is harder than the head employing ferrite and is brittle against an external force. The Sendust head is also inferior to the ferrite head in terms of its antifriction property.
A head usable for recording media of all kinds inevitably has a shorter service life or is expensive. In the VTR, use of both the evaporation tape and the metal tape necessitates use of the Sendust head. However, the short life of the Sendust head inevitably shortens the service life of the VTR.
Such being the shortcoming of the prior art VTR's, it is an object of the present invention to provide a recording and/or reproducing apparatus in which the contact of a head with a recording medium is controlled to ensure long life as well as to render the apparatus operable on recording media of at least two different kinds, advantageously utilizing their characteristics.
It is another object of the invention to provide a video signal recording and/or reproducing apparatus in which the contact of a rotary head with a magnetic tape is controlled by selecting, from two different kinds of rotary heads a head that is suited for the magnetic tape being used.
It is another object of the invention to provide a rotary head assembly which controls contact of a rotary head with a magnetic tape.
Still another object of the invention is to provide a head driving device of a simple structural arrangement, which is capable of driving a head perpendicular to a sliding contact plane between the head and a recording medium.
These and further objects and features of the invention will become apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawings.